Artificial respiration or resuscitation techniques now being used to revive a victim without normal respiratory function involve the introduction of a fluid, such as oxygen or air, directly into the patient. In the most rudimentary form, this is accomplished by "mouth-to-mouth" respiration where a medical attendant or the like exhales directly into the mouth of the patient, thereby forcing air into the lungs.
A more satisfactory technique involves intubation, where a hollow tube is inserted through the mouth and into the proximity of the larynx. Yet another improvement involves sealing off the esophagus in order to prevent diversion of respiration effort to inflation of the stomach. In addition, an open esophagus can result in aspiration of the stomach contents through the esophagus into the mouth and throat, and subsequently into the respiratory passages. The occurrence of such backflow could result in the inability of the lungs to receive the fluid needed for respiration.
One prior art device is an endotracheal tube which is inserted through the mouth of the patient, through the laryngeal region and into the patient's trachea. Yet another prior art device, depicted in U.S. Pat. No. 3,683,908, embodies an esophageal obturator where an elongated tube carries an expandable device into the patient's esophagus, the expandable member to obturate, or block off, the esophagus. Still another prior art device is described in an article by Elam et al., Advances in Cardiopulmonary Resuscitation, 1977, pages 65-72, wherein an esophageal obturator is combined with a pharyngeal cuff to obviate the need for a sealing face mask. U.S. Pat. No. 3,874,377 to Davidson discloses an insertable tube including a rotating valve-like member for use in sealing either the esophagus or the trachea.
In dealing with emergency conditions requiring artificial resuscitation, it is not uncommon to encounter associated cardiac arrythmias. Prior art devices have included a single internal electrode coupled with an external electrode to provide electrical stimulation to the heart suitable for arresting the arrythmia and/or restoring normal operation of the heart.
As noted in U.S. Pat. No. 4,090,518 to Elam, such a device requires energy levels of 15 to 20 watt seconds. Although these current levels are an improvement over the energy levels of about 400 watt seconds required by two external electrodes, the levels are significantly above the energy levels of 1-10 watt seconds where direct heart contact is made. It would be desirable to obtain defibrillation using smaller current levels to improve the portability of power supplies for defibrillation units but without the need for surgery to obtain direct heart contact.
The disadvantages of the prior art are overcome by the present invention, however, and improved apparatus for emergency artificial respiration and cardiac defibrillation are provided.